A surveyor's rod as used herein is also variously known as a surveying rod, a levelling rod, a level staff, a topographer's rod, and a stadia rod. The surveyor's rod is often a graduated wooden or aluminum rod that is used with a levelling instrument to determine the difference in height between points or heights of points above a datum surface.
A surveyor's rod can be one piece, but many are sectional and can be shortened for storage and transport or lengthened for use. Aluminum rods are often telescoping so that it can be shortened by nesting its sections inside each other. Wooden rod sections can be attached to each other with sliding connections or slip joints, or hinged to fold when not in use.
Surveyor's rods are usually graduated on one or two sides. If marked on two sides, the markings can be identical or can have different units on each side, such as imperial units on one side and metric units on the other. Surveyor's rods are sometimes used to locate an object or a location with accurate survey grade locations.
Surveyor's rods sometimes have a pointed bottom end to pin point an exact vertical elevation and horizontal location on objects and on surfaces. Typically, a surveyor's rod is used to measure a distance or height from the surface it is resting on. A measurement of height enables the surveyor or user to know the elevation at the top of rod and then know the elevation at the bottom by a method of subtraction.
Other equipment may be used with the surveyor's rod, such as a survey prism. The survey prism is typically mounted atop the surveyor's rod in order to reflect a signal back to a surveying total station. A surveying total station is a surveying instrument that integrates an electronic theodolite with an electronic distance meter. The theodolite uses a movable telescope to measure angles in both the horizontal and vertical planes. Other types of equipment may be placed atop of the surveyor's rod.